Variable Seaward Migration of Salmon
Salmon (Salmo salar) kelts from hatchery operations, when liberated in rivers and in or near river estuaries, show by the distribution of the recaptured fish an extent of seaward migration that varies from river to river, apparently in relation to the character of the estuary and river influence in...
| Published in: | Journal of the Fisheries Research Board of Canada |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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Canadian Science Publishing
1945
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f42-037 http://www.nrcresearchpress.com/doi/pdf/10.1139/f42-037 |
| Summary: | Salmon (Salmo salar) kelts from hatchery operations, when liberated in rivers and in or near river estuaries, show by the distribution of the recaptured fish an extent of seaward migration that varies from river to river, apparently in relation to the character of the estuary and river influence in the sea. For the very large St. John river (N.B.) they are mainly in the long, deepish estuary and rarely leave the zone of river influence, while for the smallish Margaree river (N.S.), with a short, shallow estuary well emptied by the tide, they are mainly near the coast outside the estuary and commonly wander to distant places in various directions. This distribution may (Margaree) or may not (St. John) correspond with that of virgin fish. The Miramichi (N.B.) with strong river influence and long estuary resembles the St. John, while the Annapolis and Philip rivers (N.S.) with slight river influence are more like the Margaree.For each river and location of liberation, the extent of seaward distribution is found to vary with differences in river discharge during a presumed settling-down period after liberation. Sharp freshets are correlated with more riverward distribution at least for a time. Heavy floods are correlated with a more seaward distribution. Continued low water is correlated with a wide distribution. |
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